1. Field of the Invention
The current invention concerns generally a method for targeted delivery of local anesthetics for treatment of cough and tussive attacks and episodes. In one aspect, the invention concerns an improved anti-tussive solution for targeted delivery of a local anesthetic to lungs by nebulization. In particular, the invention concerns an improved anti-tussive lidocaine solution for targeted delivery of lidocaine into conducting and central airways as well as a method using said lidocaine solution for treatment of cough and tussive attacks or episodes.
The solution for inhalation comprising lidocaine or another local anesthetic is administered in daily dose from about 10 mg to 160 mg. Lidocaine or another anesthetic dissolved in a normal or diluted saline is nebulized into an aerosol having a mass median aerodynamic diameter (MMAD) within a range of 3 μm to 10 μm using an electronic nebulizer able to generate a substantially monodisperse particle spectrum. The solution comprising lidocaine or any other anesthetic nebulized according to the invention described herein is deposited predominantly in the target area for cough receptors, namely in the upper, conducting, and central airways, without any substantial residue of the anesthetic found in the oropharyngeal area or in the lower lungs.
In alternative, the local anesthetic solution suitable for treatment of cough may be administered nasally, orally or intravenously when appropriately formulated for such use.
For nasal administration, the local anesthetic is formulated as drops comprising about 2.5 mg of the drug in 0.3 ml of solvent. For oral administration, 50-100 mg of the drug is administered orally once or twice daily. For intravenous administration, the daily dose is up to 2000 mg administered once or several times a day.
The method for treatment of cough, asthma and tussive asthmatic attack is safer than the treatments described previously in that the secondary undesirable symptoms such as bronchospasm, loss of gag reflex and numbing of a pharyngeal region due to anesthetic properties of lidocaine or another anesthetic compound are prevented. The method is also more efficacious because it permits use of a lesser amount of lidocaine when the solution is nebulized using electronic nebulizer and delivers this solution in shorter time. Additionally, the electronic nebulizers produce a substantially monodisperse spectrum of particles substantially within a range of 3 μm to 10 μm of which a large percentage is deposited in the central airways.